Probe systems often are utilized to test the operation of a device under test (DUT). Probe systems generally include a signal generation and analysis assembly, which is configured to generate one or more test signals for the DUT and/or to receive one or more resultant signals from the DUT. Probe systems also include a plurality of signal circuits, and each of the signal circuits may convey a respective signal, such as a respective test signal or a respective resultant signal, between the DUT and the signal generation and analysis assembly.
The signal circuits include a variety of distinct components that utilize a staged, staggered, or stepped approach to convey signals between the signal generation and analysis assembly and the DUT and/or to progressively adapt the signal circuits from a more macroscopic scale, such as may be associated with electrical connections that are made between the signal circuits and the signal generation and analysis assembly, to a more microscopic scale, such as may be associated with electrical connections made between the signal circuits and the DUT.
As an example, a plurality of wires and/or cables may define a first region of the signal circuits and may be utilized to convey the signals between the signal generation and analysis assembly and a probe head assembly of the probe system. As another example, a printed circuit board may define a second region of the signal circuits and may be utilized to convey the signals between the plurality of wires and/or cables and a space transformer of the probe system. As yet another example, the space transformer may define a third region of the signal circuits and may be utilized to convey the signals between the printed circuit board and a contacting assembly of the probe system. The contacting assembly may include a plurality of probes, and the probes may be configured to electrically contact corresponding contact pads on the DUT to facilitate transfer of signals between the probe system and the DUT.
The space transformer may adapt, or transform, an average pitch, or spacing, of the signal circuits between a first average pitch, which may be associated with the printed circuit board, and a second average pitch, which may be associated with the contact pads of the DUT. Conventional space transformers are relatively complex electrical structures that may take many weeks, or even several months, to fabricate. In addition, conventional space transformers are fabricated utilizing a layer-by-layer, or serial, process in which a plurality of layers is built up, one on top of the other, to define the space transformer. Such a serial process results in the long fabrication times that are discussed above, and the individual layers cannot be separately tested prior to assembly of the conventional space transformer. As a result, a defect in any one of the layers, of which there may be a dozen or more, may cause the conventional space transformer to be nonfunctional, adding to the fabrication time and/or cost of the conventional space transformer. Furthermore, conventional space transformers must be custom-fabricated for specific DUTs. This may result in additional costs and/or delays, especially during development of new integrated circuit devices and/or when adapting a given probe system to a given integrated circuit device. Thus, there exists a need for improved probe systems for testing integrated circuit devices.